Question

Найдите значение дроби 5x-14+x^2/49-x^2 при x=22

Помогите

Answer 1

Ответ: $\displaystyle -1\frac{1}{3} = -1.(3) \;\;.$

Решение:

$\displaystyle \frac{5x-14+x^2}{49-x^2} = \frac{x^2+5x-14}{7^2-x^2} = \frac{1(x-2)(x-(-7))}{(7-x)(7+x)} =\frac{(x-2)(x+7)}{(7-x)(7+x)} = \\\\\\\frac{x-2}{7-x} = \frac{22-2}{7-22} = -\frac{20}{15} = - \frac{4}{3} = -1\frac{1}{3} = -1.(3) \;\;.$